High-pressure hydraulic valve with pilot valve



June 5, 1951 R. F. MOORE mewmmssum HYDRAULIC VALVE WITH PILOT VALVE 5 Sheets-Sheet 1 Filed Dec. 11, 1948 W lli III June 5, 1951 R. F. MOORE 2,555,755

HIGH-PRESSURE HYDRAULIC VALVE WITH PILOT VALVE Filed Dec. 11, 1948 3 Sheets-Sheet 2 m -LEM INVENTOR. EHLPH F MOORE June 5, 1951 R. F. MOORE HIGH-PRESSURE HYDRAULIC VALVE WITH PILOT VALVE Filed Dec. 11, 1948 3 Sheets-Sheet 3 INVENTOR. RALPH ENCORE wmW ,qrrv.

Patented June 5, 1951 HIGH-PRESSURE HYDRAULIC VALVE WITH PILOT VALVE Ralph F. Moore, Shrewsbury, Mass, assignor to Wyman-Gordon Company, Worcester, Mass, a corporation of Massachusetts Application December 11, 1948, Serial No. 64,848

4 Claims.

This invention relates to hydraulic valves which are to be operated under very high pressure and which cannot be directly shifted manually.

It is the general object of this invention to provide an improved hydraulic valve construction by which the main valve is operated under the control of a pilot valve, which latter valve may be manually shifted.

A further object of the invention is to provide a hydraulic valve construction in which a main valve under heavy hydraulic pressure will be caused to promptly follow any and all movements of an associated pilot valve, and in which the movements of the main valve are preferably in the same direction and of the same amplitude as the movements of the pilot valve.

A further object is to provide a construction in which the limits of movement of the main valve in both directions are determined by the extent of movement of the pilot valve, and in which the limits of movement of the pilot valve in both directions may be separately determined.

My invention further relates to arrangements and combinations of parts which will be hereinafter set forth and more particularly pointed out in the appended claims.

A preferred form of the invention is shown in the drawings, in which Fig. l is a sectional side elevation of my improved hydraulic valve;

Fig. 2 is a view similar to Fig. 1' but showing the main valve and pilot valve in different positions;

Fig. 3 is a detail view, taken substantially along the line 33 in Fig. 2

Fig. 4 is a side elevation, partly in section, of the main valve body or casing;

Fig. 5 is an end view, looking in the direction of the arrow 5 in Fig. 4;

Fig. 6 is a sectional plan view, taken along the line 66 in Fig. 5;

Fig. 7 is a sectional end elevation of the main and pilot valves, taken along the line 1l in Fig. 8;

Figs. 8, 9 and 10 are longitudinal sectional views of the two valves, taken along the lines 8-8, 9-9 and Ill-l0 respectively in Fig. 7; and

Fig. 11 is a diagrammatic view illustrating the follow-up movement of the main valve.

Referring to Figs. 1 and 2, my improved hydraulic valve comprises a main body or casing 20 having a cylindrical liner or sleeve 2| fixed therein and having end members 22 and 23. A main valve 25 is slidable in the cylindrical recess C in the fixed sleeve 2!. The main valve 25 has a liner 2B fixed therein which has an axial passage 21 for a pilot valve 28.

The valve 28 is connected by a valve rod 35 to a rack bar 3i slidable in the end member 23 and engaged by a segmental gear 32. The gear 32 is mounted on a stud .33 (Fig. 3) rotatable in bearings 54 and 35 in an extension 35 of the end member 23. A handle 38 is mounted on the stud 33 and is provided for manual shifting of the segmental gear 32 and pilot valve 28. Stop screws 39 (Figs. 1 and 2) are engaged by the segmental ear at its limits of movement. These stop screws may be separately adjusted to vary the limit of movement in each direction.

Fixed cylindrical inward projections 48 and M (Figs. 1 and 2) are provided on the inner faces of the end members 22 and 23 and slidably support the end portions 25a and 25b of the main valve 25.

A cup washer 42 (Fig. l) is secured to the inner end of the projection 40 by a disc 43 and prevents leakage between the main valve 25 and the end projections 42. A double cup washer M having both inner and outer flanges is secured to the extension 4| by a ring 45 and prevents lealrage between the main valve 25 and the projection 41 and also around the valve rod 30.

Referring to Figs. 4, 5 and 6, the main body or casing 21 has a cylindrical axial passage 5&3 and is provided with series of annular channels 5|, 52, 53, 54 and 55. The passage 53 is connected to a supply pipe 65, through which constant hydraulic pressure is supplied. This pressure is commonly extremely heavy and may reach or exceed 5500 lbs. per square inch.

The end channels 5! and 55 are connected by passages 63, 64 (Fig. 6) to a longitudinal passage 55 in an exhaust manifold having a discharge pipe 51 (Fig. 5). The remaining channels 52 and 54 are connected to pipes i5 and H (Fig. 6), which in turn are connected to opposite ends of any hydraulic mechanism to be controlled or operated by the hydraulic valve herein described. The main casing liner 2! (Fig. 1) defines the cylinder 0 and is provided with successive annular series of ports l5 which communicate with the annular channels 5! to 55 above described.

The main valve 25 (Fig. 8) is slidable in the cylinder 0 and is a free sliding fit therein. Limited hydraulic leakage past the valve 25 is considered desirable, as a certain amount of circulation through the very high pressure pump which supplies the hydraulic liquid is necessary to avoid overheating.

The main valve 25 has reduced end portions 25a and 25b and a reduced middle portion 25c. Annular passages H, 18 and 19 (Fig. 1) are thus bushing 82 having suitable packing 33 for the pilot valve rod 30.

The plug 8| and bushing 82 enclose a chamber C in which the pilot valve 23 is freely slidable. The valve 28 has reduced end portions 28a and 28?) (Fig. 9) and a reduced middle portion 28c which provides an annular channel 83. The valve 28 also has an extension 28d slidable in a bearing opening in the plug 8 I.

The main valve liner 2% has ports in three difierent planes. as indicated in Figs. 7 to 10; In plane 88, the liner 2% hasports ill, 88 and 89 (Fig. 8). The port 6? communicates through a restricted opening 98' in the main valve 25 with the annular passage it between the main valve' and the wall of the cylinder C. The port 88' connects through an open longitudinal pas-- sage 91 (Fig. 1) in the valve 25 to a space S at the left-hand end ofthe cylinder C, and the port 339 connects through a correspondingopen longitudinal passage 92 (Fig. 2) to a space S at the opposite end of the valve cylinder C.

Ports 93 and M (Fig. 8) continuously connect these longitudinal passages with the annular passages El and ES whichv surround the extension 25a and 25b of the main valve 25, and theseannular passages are continuously connected to the exhaust through the annular passages i and 55 and through the connections 53 and a: to the exhaust manifold.

The valve liner 26 (Fig. 9) is also provided with ports ml) and Nil which are in the plane of the section line iii-9 of Fig. 7. These ports 4 C and thence through the passages 88 and BI to the space S, which in turn is connected through a passage 93 to an exhaust pipe 63. The space S3 is thus vented.

The port I130 is opened and closed simultaneously with the port ms, and the main valve is brought to rest as soon' as both of these ports are covered by movement of the valve 25 to the right. Further movement of the pilot valve in the same direction will cause further movement of the mainvalve to the right, and movement of the pilot valve to the left to uncover the ports [BI and I65 will cause corresponding movement of the mainvalve to the left and discharge of liquid from the space S2 through the channel I01, port [05, passages 39 and 92, vent 94 and exhaust connection 64.

It is thus seen that every movement of the pilot valve 23, whether manually or automatically produced, will be followed immediately by a corresponding movement of the main valve 25 in the same direction and to the same extent. As soon as such movement is completed, the main valve will be locked by the closing of both ports we and H and cannot be thereafter displaced except in response to further movement of the pilot valve.

It will also be noted that both end portions of the pilot valve chamber C are at all times connected through the passages 9| and 92 to the spaces S and S which in turn are at all times connected to exhaust' Consequently, the pressures on the pilot valve 82 are at all times balanced and the pilot valve is freely movable, re-

'" gardless of the heavy pressure controlled thereby.

' as set forth in the claims, but what I claim-is:

connect into a channel or keyway IE2 inthe liner 26 which is open at its right-hand end as shown in Fig. 9;

In the plane lil@o'f Fig. 7', the liner 2% has:

The operation of my improved hydraulic valve will now be described, with particular reference to diagrammatic Fig. 11 in which the various ports and passages are transferred to a common plane. pilot valve 23 has been moved to the right in the main valve chamber C far enough to open the ports tell and its. Hydraulic pressure will then be applied through the pipe (iii, annular passage '49 and restricted opening 95 to the annular passage 82, and thence through the port lite" and channel W7 to the space 52' at the left of the main valve 25: Pressure is thus exerted between the valve 25 and the fixed casing'projection M, and the valve 25 will be moved to the right until the port I06 is again covered by the valve 28.

During such movement of the valve 25, the space S3 at the right-hand end of the valve 25 is connected through the channel I92 and port I09 to the left-hand end of the valve chamber It is assumed in Fig. 11 that the l. A hydraulic valve mechanism comprising. a casing having. a valve chamber therein provided with hydraulic pressure and exhaust connections,

a main valve slid'abl'e in said chamber andhaving a closed passage therein, a pilot valve slidable in said closed passage in said m'ain valve,

means to continuously vent both ends of said closed passage to the exhaust connection of said main valve, selective means to move said'pilot valve freely in either direction, and hydraulic connections controlled by said pilot val ve' and effective to admit liquid under pressure to the mechanism as set forth in claim 1, in which the- 4. A hydraulic valve mechanism comprising a-- casing havinga valve chamber therein provided with hydraulic pressure and exhaust connec-' tions, a, main pisto-n'valve'slidable in-said chamber and having a closed axial passage therein,

a pilot piston valve slidablein said closed.- axial passage in said main valve, means to continu- REFERENCES CITED 011513 Vent both a of clos'ed passage to The following references are of record in the the exhaust connectlon of sa1d mam valve, selecfile of this patent:

tive means to move said pilot valve freely in 1 either direction, and hydraulic connections con- 5 UNITED STATES PATENTS trolled by said pilot valve and effective to admit Number Name Date liquid under pressure to the indicated end of 151,667 Loretz June 2, 1874 said chamber and to move said main valve in 929,206 Gelpke July 27, 1909 said chamber in the same direction and to the 1,119,640 Roettger Dec. 1, 1914 same extent as said pilot valve has been moved. 10 1,125,825 Englesson Jan. 19, 1915 1,743,732 Seewer Jan. 14, 1930 RALPH F. MOORE. 2,455,315 Rose Nov. 30, 1948 

